Top surface of a floor mat



FIG. 1 is a top plan view of a first embodiment of the top surface of a floor mat according to our novel design; and,

FIG. 2 is a top plan view of a second embodiment of the top surface of a floor mat according to our novel design, the sole difference from the first embodiment resides in the opposite alternating pattern of light to dark areas. 

The ornamental design for a top surface of a floor mat, as shown and described. 